Purpose and Program Characteristics: The purpose of this multidisciplinary research training program, which draws both personnel and principles from epidemiology, psychiatry and the social sciences, is to increase the number of psychiatric epidemiologists who, by virtue of their ability, motivation and training, are capable of making significant contributions to understanding the etiology and course of psychiatric disorders. To achieve these goals, the program provides rigorous training in psychiatric epidemiology through five program components: 1) coursework in general and psychiatric epidemiology, 2) coursework in methodology and statistics, 3) coursework in clinical and diagnostic issues, including the opportunity for patient contact, 4) field placements in ongoing research and the development of fellow-initiated research projects, and 5) a weekly faculty-fellow seminar. Trainees: The trainees in the program are selected from the disciplines of epidemiology, psychiatry, psychology, and the social sciences. Predoctoral fellows must be enrolled in a Ph.D. program. Postdoctoral fellows must have a Ph.D. or M.D. degree. Since the strength and character of this program depends in part on its size, we are requesting funds for nine postdoctoral and five predoctoral fellows. Training Facilities: The primary training facility is the Division of Epidemiology, School of Public Health, Columbia University in collaboration with the Department of Psychiatry.